The method and system for providing multimedia content service based on communication systems through a wired communication network such as a very-high speed Internet or through a wireless communication network such as IMT 2000 are being noted.
In particular, functions of transmitting/receiving still pictures, moving pictures, and music files such as MP3 files, as well as voice and text, through wired/wireless terminals have been added to the terminals, or have been implemented through connection with external apparatuses. Accordingly, the technical foundation for transmitting/receiving multimedia content files by wire or wirelessly is being laid down, and the technical foundation for enabling the consumers to create multimedia content files by themselves and to spread the created multimedia content files through wired/wireless communication networks is being laid down also.
Meanwhile, since a user terminal constituted by a wired or wireless terminal cannot have a media reproduction-related performance capable of reproducing all innumerable media (e.g. still pictures and moving pictures) provided as multimedia content files, generation of media which cannot be reproduced is inevitable.
There are innumerable types of media, including text, a still picture, a moving picture, etc., wherein types of the audio include mpa, mp3, mp2, wma, way, etc. based on file extensions for reproduction, and types of the moving pictures include wmv, avi, divx, asf, mpg, etc. based on file extensions for reproduction.
Since innumerable types of media exist, as described above, it is not easy for a user terminal to have a codec capable of reproducing all types of media.
Moreover, since the user terminal generally has relatively lower processing capability than a personal computer (PC) in terms of performance of reproducing various media, the user terminal has a poor processing capability in terms of hardware performance required for displaying corresponding media on a screen of the user terminal, which, together with the fact that the mobile terminal has no codec, limits media which can be reproduced.
Additionally explaining the hardware s processing capability of the user terminal, the hardware s processing capability frequently reaches its limit when reproducing two or more pieces of media, rather than when reproducing one piece of media.
Generally, a user terminal reproducing two or more pieces of media (e.g. moving pictures) includes a memory for storing compressed moving-picture files, a first decoder for decompressing and outputting a first moving picture file stored in the memory, a second decoder for decompressing and outputting a second moving picture file stored in the memory, an image processor for combining and outputting moving picture frames output from the first and second decoders, a display unit for displaying data output from the image processor, and a controller for executing a process for re-production of media.
The memory may be one or more flash memories, one or more hard disks, one or more optical disk storage devices, or a combination thereof.
Each of the first and second decoders is constituted by a digital signal processor which has a flexible mechanism capable of reproducing files compressed in a plurality of formats. Each decoder may support one or more formats among MPEG-4, H.263, MPEG-2, etc.
Although the two decoders operate at the same time, the two decoders may reproduce moving picture files of mutually different formats.
Each decoder reproduces a specified moving-picture file, starting at an appointed time point. For each decoder, a double-speed play function, a low-speed play function, etc. are supported.
Decoders having these functions are commercialized and provided, and codecs associated with the decoders decompress files and output image frames in standard formats, such as YUV or RGB.
The image processor may enlarge or reduce the respective input image frames, or may combine two images.
For example, two moving pictures may be reduced and displayed on a screen divided into two areas, respectively. Otherwise, one moving picture frame may be displayed as a main screen over the entire screen, while the other moving picture frame is reduced and displayed in the form of Picture-In-Picture (PIP).
However, such a conventional user terminal can reproduce and output two pieces of media, especially, two moving pictures, on a terminal s screen at the same time, but it must have superior performance in order to reproduce three or more moving pictures at the same time. Also, since all conventional user terminals are not designed to reproduce two moving pictures through the internal operation thereof, a moving picture which cannot be reproduced in a user terminal may appear.
Moreover, during a service where predetermined media are provided from a server to a user terminal, when one or more pieces of media constituting each element are lost due to transmission environments while they are being transmitted to the user terminal, a negative effect is exerted upon the overall service performance. Therefore, generally, the server retransmits lost media, or transmits an error correction code so that media can be recovered when a loss occurs in the media.
However, reflectively transmitting an error correction code, or retransmitting corresponding media in order to recover a media s loss is inefficient in terms of bandwidth limitation in communication environments, and in terms of service operation.
Therefore, a method for overcoming these problems is required.